[Natural birth control using the Billing's method].
Hansen
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EL
Jødal
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E
D000328:Adult; D003267:Contraception / Q000379:methods*; D005193:Family Planning Services; D005260:Female; D006801:Humans; D012252:Natural Family Planning Methods; D014621:Vagina / Q000378:metabolism
Naturlig fødselsregulering med Billingsmetoden.